Train dispatching system for railroads



Oct. 29, 1935. w. w. WENHOLZ TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed Nbv. 14, 1929 2 Sheets-Sheet 2 INVENTO- W ATTORNEY Patented Oct. 29, 1935 UlED OFFICE TRAIN DISPATCHING SYSTEM FOR RAILROADS Application November 14, 1929, Serial No. 407,127

21 Claims.

This invention relates to train dispatching systems, and more particularly to improvements in means for determining the direction of trafiic by sequence of lever operations, as applied to single track railroads, or other stretches of track equipped with block signalling for train movement in both directions.

In one type of train dispatching system, to which the present invention more particularly relates, such as shown and described, for example, in the application of S. N. Wight, Ser. No. 120,423, filed July 3, 1926, when applied to a single track railroad, the direction of trafiic for the stretch of single track between passing sidings is determined by the sequence of operation of the levers associated with the adjacent ends of these passing sidings, utilizing the interconnected line circuits, sometimes termed the tumble-down circuits, which are characteristic of the well known absolute-permissiveblock signalling system for single track railroads. In such a type of system, particularly if color light signals are employed, there is sometimes so much delay in the operation of the tumble-down circuits that quick operation of the levers in sequence fails to set up the desired direction of trafiic. Also, in this type of system, it may happen that the temporary shunting of an intermediate track circuit in the stretch of single track between the sidings will cause a reversal of the direction of traffic previously established by the sequence of lever movements.

With these various considerations and objections in mind, it is proposed in accordance with the present invention to provide inter-controlled stick relays at each end of each siding, controlled by the signal control line relays and by the operator, in such a manner as to establish and maintain the desired direction of traific selected by the operator for the normal train movements encountered in practice, thereby obtaining the advantages of a dispatching system, in which the direction of traffic is determined by sequence of lever operation, and at the same time obviating the disadvantages of an improper direction. of trafiic set up, or a lock-up condition, or the like, which might occur in this type of dispatching system if not provided with the improvements of this invention.

The particular objects, purposes and characteristic features of the invention will be in part specirically pointed out, and in part apparent, as the description progresses.

In the accompanying drawings, Fig. 1' illustrates one specific application of the invention to a stretch of single track between two pa sing Sidlngs; and Fig. 2 illustrates separately the signal control and tumble-down circuits, which are not shown in detail on Fig. 1 to avoid confusion, it being understood that Figs. 1 and 2 should be considered together for a showing of the various re- 6 lays and circuits involved.

While the invention may be applied to various track layouts, it has been shown, for the purposes of explanation and with no intent to limit its field of application, a in connection with a typical 10 stretch of single track 0 between two passing sidings PSI and PS-Z, assumed to be equipped with the well known A. P. B. type of block signal circuits, such as disclosed, for example, in the patent to S. N. Wight, No. 1,294,736 dated February 18, 1919, together with the additional signals and circuit modifications required for the application of the type of dispatching system disclosed in said Wight application.

Referring to the right hand or east end of the v passing siding PS-I, the entering signals, governing west bound traffic on the main track and onto the siding are designated l and IA respectively, and the leaving or starting signals governing trafiic on the main track and from the siding are designated 2 and 2A, respectively. Similarly, the west end of the passing siding PS2 isequipped with entering signals 4 and 4A, and starting or leaving signals 3 and 8A; and the other ends of these two sidings are provided with entering and starting signals 5-5A, 6--6A, l'lA, and 8-8A. Referring to Fig. 2, twoopposite intermediate signals 9 and H) are shown; but any desired number of intermediate signals may be employed, arranged in opposite or staggered relation, as desired. For simplicity, these various wayside block signals have been illustrated conveniently as of the semaphore type, but may be color light signals, or any other suitable form of block signals. 40'

These signals are each controlled by a line relay, designated l H, 2H, etc, in accordance with well known practice, these line relays being preferably polarized to provide for three indications.

The line relays for these signals are in turn controlled by track relays. The various track sections involved in the stretch of track shown are illustrated in a conventional and well known manner, with track batteries and track relays, these track sections being designated I 2 to '2 I, and their corresponding track relays I2T, I3T, etc.

In addition to the line relays controlling the enteringand leaving signals at the ends of the sidings, these signals are controlled by additional relays, designated G. For example, the enterin i signal 4 is controlled by the line relay 4H and the relay 4G; and the entering signal 4-A by the relay 4AG. The starting signal 3 is controlled by the line relay 3H and the relay 3G; and the starting signal 3A is controlled by the line relay 3H and the relay 3AG. For simplicity the relays IAG and ZAG, controlling the signals IA and 2A, are not shown.

The switches at the end of each passing siding are intended to be operated by a suitable power operated switch machine, with suitable approach locking and detector track circuit control, as shown and describe-d in said Wight application, these switch machines and their control circuits being omitted in the accompanying drawings for the sake of simplicity.

Each of these switch machines is provided with point detector contacts, operated in accordance with the position and locked condition of the points, and directly, or indirectly through neutral polar relays, closing contacts in the normal and reverse operation of the switch, these contacts being employed in connection with the control of the signals at the switch, and also of the directional stick relays, more particularly constituting the improvement of this invention. Such point detector contacts are shown diagrammatically for the switches at the adjacent ends of the two passing sidings, as comprising contact members 22-21, movable from the normal position shown to the reverse position, indicated by dotted lines, into and out of engagement with stationary contacts, indicated by arrows.

The power operated switches at each end of each siding, and the signals governing traffic in both directions on the main track and on and from the sidings, may be controlled by the operator or dispatcher, subject to track circuit control, by the energization of neutral polar relays, one for each siding end, governed over a separate line circuit from the dispatchers office. These two control relays for the east end of the passing siding PS-l and the west end of the passing siding PS-2 are designated IZ and 22; and the levers in the dispatchers office DO, by which these relays are controlled, are designated L'-l and L-Z. The energization of these relays I Z and ZZ by movement of the levers L-l and L-2, over the line circuits extending to the dispatchers office, will be evident Without tracing the circuits in detail.

In addition to the foregoing relays and other devices, characteristic of the type of dispatching system, to which this invention relates, there is provided for the purposes of this invention, for each end of each siding, two directional stick relays, as IDR and ZDR. The control circuits for these relays and their operation will be explained hereinafter, after the operation of the dispatching system has been briefly summarized. Considering first the signal controlling circuits, shown in Fig. 2, and more particularly the socalled tumble-down circuits for the east bound signals, the line circuit for the relay 2H includes the front contacts 39, 3!, and 32 of the track relays MT, I5T and IBT of the track sections between signal 2 and the intermediate signal l9, governing trafiic in the same direction, and also the front contact 33 of the relay 49H in multiple with the front contact 34 of the usual stick relay ms of the A. P. B. system. The line circuit for the relay IIJH includes the front contacts 35, 35 and 31 of the track relays HT and l8T and WT of the track sections I118, and I9, circuit con'trollers 38 and 39 for the signab 3A and 3,

closed only when these signals indicate stop, and a back contact 40 of the directional stick relay BDR.

Similarly, the line circuit for the relay 31-1 includes the front contacts 4|, 42, and 43 of the track relays I9T, I8T, and HT, and the front contact 44 of the line relay 9H, in multiple with the front contact 45 of the A. P. B. stick relay 98. The line circuit for the relay 9H includes the front contacts 46, 41 and 48 of the track relays IBT, i5T, and MT, the circuit controllers 49 and 59' of the signals 2A and 2, closed with these signals at stop, and the back contact 5| of the directional stick relay ZDR.

Disregarding for the moment the control by the directional stick relays ZDR and 3DR, by reason of these tumble-down circuits, briefly stated, when the dispatcher operates a lever to clear either the signal 2 or 2A, depending upon the position of the switch, for the purpose of permitting an east-bound train movement, the clearing of this signal 2 or. 2A opens its circuit controller 49 or 50 and this signal de-energizes the relay 9H, putting the signal 9 to stop; and since the stick relay 9S is down, this de-energizes in turn the relay 3H, putting the signals 3 and 3A to stop, so as to block opposing moves. Similarly, if the lever were operated to clear the signal 3 or 3A for west-bound movement, the relays IGH and 2H would be de-energized to put the opposing signals l0 and 2-2A to stop.

' Bearing in mind these tumble-down circuits, and the interconnection between opposing signals, it will be evident after some consideration, that if the operator should operate the levers for the adjacent ends of the sidings too quickly, there would be a conflict in the operation of the relays and a tendency to set up traific in both directions. It can also be understood that, with traffic set up in one direction, and a momentary shunting of intermediate track relays, putting the signals for traffic in both directions to stop, upon removal of this shunt, the subsequent energization of the relays may be such as to reverse the direction of trafiic previously set up. The present invention deals more particularly with means for obviating these disadvantages which are especially pronounced when there are a number of intermediate signals, and there is a substantial delay in the action of the tumble-down circuits, due to the number of intermediate signals, or the use of color light signals.

Considering now the control circuits for the signals 3, 3A, 4 and 4A, the entering signal 4 is controlled by the neutral and polar armatures 83 and 84 of the line relay 4H, the point detector contact 25 in the normal position, and the front contact of the relay 4G. The energizing circuit for the relay 4G may be traced from (-I) through the front neutral contact 55 of the relay ZZ, wire 56 polar contact 51 of relay 22, wires 58 85, front contact 81 of the directional stick relay 4BR, wire 88, and relay 4G to The leaving signal 3 is controlled by the neutral and polar contacts 63 and 89 of the relay 3H, point detector contact 2'! closed normal,

and the front contact 99 of relay 3G. The relay 3G is energized through the back contact 81 of the directional stick relay 4BR, over the same energizing circuit as heretofore pointed out for the relay 4G. In other Words, when the relay 22 is energized by the operator with a polarity corresponding to the normal position of the switch, or a train movement on the main track,

either the relay 4G or the relay 3G is energized.

to clear the signal 4 or the signal 3., dependin upon either the directional stick :relay 4BR :being energizing or de-energized, and provided the switch points are in the normal position to close point detector contacts 25 and 21..

The entering signal 4A, for governing train movement unto the siding, is controlled by front contact 9| of the relay iAG; and the signal 3A, governing train movement from the siding, is controlled by the front contact 92 of the line relay 3H, and front contact 53 of the relay SAG. The relays lAG and 3AG are connected in multiple in series with the point repeater detector contact 25, closed in the reverse position, and the neutral and polar contacts 55 and 53 of the relay 22. Thus, if the operator energizes the relay ZZ with a polarity to operate the switch to the reverse or take-siding position, the signals 3A and 4A may be cleared.

Operation.Considering now the operation of the improvement of this invention, referring to Fig. 1, the pick-up circuit for the directional stick relay EDR may be traced from through the front contact 55 of the control relay IZ, wire 55, polar contact 5! of the relay IZ, Wires 58 and 59, relay IDR, wires 65 and 6!, and front contact 52 of the relay 5 H to This directional stick relay IDR, once energized, is maintained energized by a stick circuit through the front contact 55 of the neutral armature and polar contact 51 of the relay lZ, wires 58 and 59, winding of the relay lDR, wires 60 and 65, and front contact 66 of the relay IDR, independently of the relay l H.

The pick-up circuit for the other directional stick relay ZDR may be traced from through the front neutral contact 6? of the relay I Z, wire 53, back contact 69 of the relay IDR, wire 75, relay 2BR, wires ii and 12, and front contact 13 of the relay 21-1. The stick circuit for this relay ZDR includes its front contact 14, wire 15, switch repeater contacts 23 closed normal or reverse, and wire T5.

The directional stick relays 3BR and 4BR, have similar pick-up and stick circuits, which need not be traced in detail.

It will be noted that the pick-up circuit for the directional relay IDR is closed at the relay lZ only when this relay is energized with one polarity, which corresponds to the normal position of the switch, that is, the position for a train movement on the main track; whereas the pick-up circuit for the other directional relay ZDR is .established at the relay IZ, whenever it is energized with either polarity. Also, these relays IDR and ZDR may be energized only if their corresponding line relays II-I and 2H are energized. Furthermore, and this is an important feature of the circuits embodying the invention, the pick-up and stick circuits for the relay 2DR include the back contact 65 of the relay IDR, so that, if the relay IDR. is energized, the other relay 2BR cannot be energized, or if energized, is automatically de-energized. Another feature of the control of these directional stick relays, is that the stick circuit for the relay ZDR includes the point detector contacts 23, closed with the switch points either in the normal or reverse posiiton, but open while the switch points are being operated from one position to the other, so that, if the relay 2DR. is maintained energized by its stick circuit (the relay 2H being de-energized) a movement of the switch drops the relay ZDR.

Considering now the function and operation.

of the directional stickfrelays and their control circuits, more particularly characterizing the presentv invention, in connection with the sequential operation of the levers to set up the direction of traffic, it should be noted that preference is given to the directional stick relay, as IDR,

which permits clearing of the entering signal, as,

the signal I, for a train movement on the main track. In other words, if the lever L-l is moved .to a position, corresponding to a train movement on the main track, while the adjacent lever is in the neutral position, and while there are no trains present, the direction of traffic established at the right-hand .or east end of the siding PS-l is toward this siding. If there is to be a train movement on the main track away from the siding, it will be evident that either a train will be present on the main .track opposite the siding, ready to leave, or else levers will have been operated in a way to set up traflic through the siding; and in this case, the preference is destroyed. Putting it another way, in the ordinary manipulation of the levers, they are operated in sequence in front of a train; and the presence of such a train, at the time of a lever operation, will destroy this preference of control of the directional stick relays, as and when required, and in such a way that, irrespective of how quickly two adjacent levers are operated in sequence, the corresponding direction of trafiic is established and maintained, so as to obviate the disadvantages heretofore pointed out. A study of the operation of the system for some typical train movements will make clear how these directional stick relays accomplish this desirable result.

Assuming an east bound train movement (from left to right) on the main track; and as a simple case, assume that the train is standing on the main track opposite the passing siding PS-I. The presence of this train breaks the line circuit for the relay IH (see Fig. 1), which may be readilytraced through the front contacts 96, 91, and 98 of the track relays I'ZT, 1ST, and MT. If now the operator moves the lever Li to a position, corresponding to a movement on the main track, and energizes the relay t2 toclose its neutral and polar contacts 55 and 51, the directional stick relay IDR. is not energized, since its pickup circuit is broken at the front contact 52 of the line relay lI-I, while the relay ZDR is energized, permitting the energization .of the relay 2G to clear the signal 2., and preventing energization of the relay IG clearing the signal I.

The energization of the relay 2DR, opening its back contact 5i (see Fig. 2) acts through the tumble-down circuits to de-energize the line relays 9H and 3H for the opposing West bound signals; but suppose that the operator moves the other lever L2 and energizes the relay 2Z (Fig.

1), before these tumble-down circuits are effective to de-energize relay 3H. In this case, the direction relay QDR is picked up, and the entering signal 4 is cleared, maintaining the desired direction of. trail-lo, without being dependent upon the action of the tumble-down circuits. The clearing of this. signal l would de-energize the line relay for the entering signals 5 and 5A at the opposite end of the passing siding PS-Z, in thesame way'as the clearing of the signal 8 de-enresponding to the relay 2DR, and thereby establishing an east bound direction of traflic.

Thus, in accordance with this invention, as shown by the example given, the desired direction of trainc is established, notwithstanding the delay in the action of the tumble-down circuits, and quick operation of the levers in sequence.

As a further example of the operation of the system, assume that there is a west-bound train on the main track of the opposite siding PS-2, Waiting for an east-bound train to arrive and take the siding. In this case the operator, after setting up east bound traffic past the siding PSI, would operate the lever L-Z to a position to energize the relay 22 with a polarity of current, corresponding to movement of the switch at the west end of the siding PS-Z tothe reverse position, that is, movement of the polar contact 51 to the left. Under these conditions, therelay iDR. is not energized, its pick-up circuit being broken at the polar contact 51 of the relay 2Z. If the lever L-2 were operated before the tumble-down circuits are effective to de-energize' the relay 3H, the directional stick relay BBB. is energized, and is maintained energized by its stick circuit even though the relay 3H may later drop. On the assumption that the switch is in its normal or main track position, which is ordinarily the case, since in practice the operator finds it expedient to leave the switches in the normal position, the switch at the west end of the passing siding PS2 must be operated from the normal to the reverse position, for the train movement under consideration; and during this operation, the opening of the contact 26 breaks the stick circuit for the relay 3DR, which consequently is deenergized, and cannot thereafter be energized by its pick-up circuit, which is broken at the front contact of the line relay 3H. This permits the clearing of the east bound signals 2 and I0 (see Fig. 2). Also, the proper entering signal 4A is cleared, once the switch has assumed the reverse position, the leaving signal 3A being held at stop, because the front contact 92 of the relay 3H is open.

After the east-bound train has entered the siding PS2, the dispatcher operates the lever -L2 to energize the control relay 22 with a polarity to cause the switch to return back to its normal position, having in the meantime placed the lever Ll in the neutral position, de-energizing the relay IZ, this being usually done in the ordinary manipulation of the system as soon as the eastbound train has passed the east end of the siding PSI. This movement of the lever L-2 energizes the directional stick relay 3BR, the line relay 3I-I being energized. During movement of the switch, the stick circuit for the relay 3DR is broken at the point detector contact 26, but this relay is held energized through its pick-up circuit. The other directional stick relay 4BR is not energized, because the presence of the westbound train de-energizes the line relay 4H. The picking up of the directional stick relay 3DR breaks at its back contact 40 (see Fig. 2) the line circuit for the relay lllI-I, which in turn breaks the line circuit for the line relay 2H, thereby putting the opposing signals IO, 2 and 2A at stop. Even if the operator should have moved the lever L-l quickly after the lever L*2, and beother words, the preference of trafiic direction is nals 2 and ill (see Figure 2).

effective for the east end of the siding PS-l, since there is no east-bound train present, or adjacent levers operated, to destroy this preference.

In the foregoing explanation, the de-energization of the line relay 4H to prevent energization of the preferential directional stick relay ADR, and thus permit the energization of the other relay SDR, has been assumed to be due to the presence of a train on the main track opposite the siding PS2; but movement of levers to set up traffic through the siding has the same effect. Suppose, for example, that there is a west-bound train approaching the siding PS2. To advance this train, the operator will have moved the levers (not shown) associated with the siding next to the east of the siding PS-2 and associated with the east end of the siding PS-2, with the result that the directional stick relay 5DR is energized, in the same way as the relay 4DR is energized, as before explained, the preference being given to the entering signal 5. This energization of the relay 5BR breaks the circuit for the line relay 4H, so that subsequent movement of the lever L2, either quickly or after an interval of delay,

results in the energization of the leaving directional stick relay 3DR. In this connection, it should be understood that, since no tumble-down circuits are involved in the control of the line relays, as IE and 4H, for the entering signals, the de-energization of these line relays occurs very quickly, and in less time than the control relays, as iZ and 22, would be energized by any ordinary sequential movement of the levers.

As a still further example of the operation of the directional stick relays, assume two east bound trains following one another, with one train on the stretch of main track opposite the siding PS2, and the following train about to go by the siding PSI. In this case, the operator moves the lever Ll to the normal position, This picks up the relay ZDR, as above pointed out, since the pick-up circuit for the relay IDR is open at the front contact 62 of the relay I H, which is de-energized due to the presence of the following train. Upon movement of the lever L--2 to the normal position, for train movement on the main track, and assuming this operation of the lever to occur before the tumble-down circuits are effective, the relay 4DR, which would ordinarily have the preference, cannot be energized, because its pick-up circuit is broken at the front contact 83 of the line relay 4H, which is maintained de-energized by the presence of the forward train. Consequently, in this case, the relay 3BR, corresponding to a west bound train movement is picked up, if the lever L-2 is moved before the tumble-down circuits are effective, and holds at stop the east bound sig- This condition exists until the leading train in question has advanced far enough to permit energization of the line relay 4H, whereupon the relayDR, is picked up and drops relay 3BR permitting clearing of the east bound signals.

If the two east bound trains had not been spaced as far apart as in the case just assumed, the operation just described would not have occurred, and there would not have been the train delay ,just explained. To illustrate, if the forward train had been on a stretch of single track 0 between two passing sidings PS| and PS--2 at the time the lever Ll was operated to set up east bound traffic for the following train, the presence of the forward train would have held the line relay 3H deenergized, and would not have permitted the energization of the relay 3BR, with the result that the directional relays would have been operated properly, the home relay 2I-I picking up as soon as the forward train 5 has advanced far enough into the single track section 0.

As a still further example of the operation of the directional stick relays, assume that an eastbound train is to pass another east -bound train at the siding PS-l. 'Irafiic for the fcllowi'ng' east-bound train will be set up by the pas'sing' siding PSI in the same way as described, the relay 2DR being energized. As soon as this following train has passed the siding, and the operator wishes to let the train on the siding Psl move out, he reverses the lever L-l' to cause the switch to assume the reverse position. I he relay IDE is not energized, even though the line relay IE is energized, because the polar contact 51 of the relay I2 is open. As soon as the train, whichhas passed beyond the siding PSI,- has advanced beyond the signal I 0 (see Fig. 2), so that the line relay 2H may be energized, the relay ZDR. is picked up, and breaks at its back contact 5| the circuit for the line relay 9H; thereby holding at stop the opposing signal 9, and

likewise the opposing starting signals 3 and 3A. When the switch assumes its reverse position, the relay ZDR is maintained energized by its so stick circuit. Also, the signal 2A will then clear,

permitting the train on the siding to advance.

There are various other possible train movements that might be considered and discussed in detail, but the foregoing would appear to be sufii- 35 cient to indicate the advantages and limitations of the org-anizationof the: present invention in connection with the particular typeof system under consideration, where direction oftr-afiic is determined by sequence of lever operation and 4 the operator may accidentallyor carelessly op erate the levers too quickly. Itwill be found, upon analysis of the operation ofthe directional stick relays for various train movements, that for the'normal train movement's encountered in- 45 practice, the directional stick relays, with the preference given to the entering signals, serves to bring about the desired direction of traflic.

One exception is a movementfrom one siding to an adjacent siding; but if the sidingswere 50 eq plied with track circuits, the principles of this invention coiild be extended, as will beevident to one skilled in the art, so asto' take care of such a train movement.

While the invention is specially applicable to traffic is established by the sequence of lever" cation, and further that various modificationsand adaptations may be made in the particular arrangement of relays and circuits shown and described without departing from the invention.

65 What I claim is 1. In a dispatching system, the combination with a'track switch, signals adjacent said switch governing traffic in opposite directions over it,

and means under the control of the operator from 70 a distant pointfor clearing asignal for gov-- erning traflic in one direction only'andincludingmeansfor automatically" enforcing the clearing of the signal governing tr'a'fiic toward the points' 01 said switch in" preference to the'op posing signal.

a dispatching system for single track railroads; of the type described, in which the direction of a distant point for governing said signals, and 5 means controlled by said relay and responsive to the presence of trains near said switch for causing the clearing of a signal governing trafi'ic toward the switch in preference to a signal governing traffic in the opposite direction; 1b

3. adispatching system of the type described for single track railroads, the combinationvvith signals adjacent to a switch at the end of a passing siding for governing trafiic in oppositedirections over the switch, of control'means 15 including two relays so interconnected that one is open circuited if the other assumes its attracted condition and controllable from a distant point and tending to clear .the signals for both directions of trafiic bu't causing the clearing of a 20 signal governing traffic toward the passing siding in preference to the opposing signal, thispreferencebeing effective when the single track section joining this and another passing siding is not occupied by adeparting train and there is 25 no train presenton the main track opposite the siding.

4. In a dispatching system of the type described a power operated switch, signals governingtraflic in oppositedirections over said switch itsdifferent positions,- control' means operable from a distant point for governing the operation of said switch and for causing said signals to clear dependent upon the position of the switch, and means governed by said control means and responsive to the presence of a train on the main track adjacent said switch for causing the clearing of a signal governing .trafiic toward said switch in preference to a corresponding opposing signal; 40

5. In a dispatching system, the combination with a stretch of single track and passing sidi-ngs-at its ends ,'a starting signal at each siding governing trafiic toward. the other siding, line circuitsinterconnecting said signals to cause the clearing of either signal to prevent the clearing of the opposing signal, the control relay at each siding operable from a distant point, and a stick relay at each siding governed by the correspondingcontrol relay and responsive to the presence oftrains on the main track opposite that siding for-'preventing the clearing of the starting signal at that siding.

6-. In a dispatching system of the type described,the' combination with signals at the end of a passing siding governing traffic in opposite directions in accordance with the position of the switch, two stick relays adjacent said switch governing said signals, one stick relay controlling the other, and means operable from a distant oint er controlling said stick relays;

7. In a rnanua'lly controlled train dispatching system, the'combination with signals at the end of a-- passing siding governing trafiic' in opposite directions, two normally de-e'nergizd stick relays governing said signals, the pick-up circuit for one stick relay includinga back contact of the other, and means'controllable from a distant point for selectively closing the pick-up circuits for one or both of said stick relays. 8: In a dispatching system of the character described, the combination with a power operated switchat theend of the passing siding and Sig na'l'sfgoverning'traflic in opposite directions over said" switch, of a" c'ont'roi rei'ay operable from a; 7.

distant point for governing the position of said switch, and two directional stick relays controlled by said relay for governing the indications of said signals, one of said stick relays when energized preventing the energization of the other.

9.In a signaling system of the character described, the combination with a power operated switch at the end of a passing siding and signals governing traffic over said switch in opposite directions on the main track, a neutral-polar control relay operable from a distant point for governing the position of said switch, a stick relay selectively controlling the clearing of said opposing signals, and a pick-up circuit for said stick relay including both a neutral and polar contact of said control relay.

10. In a dispatching system of the type described for single track railroads, in which the direction of trafiic between passing sidings is established by the sequence of operation of control levers associated with said sidings, the combination with inter-connected starting signals governing traific in opposite directions over a stretch of single track between passing sidings, of means including two interconnected directional stick relays for holding said signals at stop and thereby permitting train movement toward the sidings in preference to train movement away from the sidings.

11. In a train dispatching system, the combination with a stretch of single track between passing-sidings, a power operated switch at each end of said stretch, starting signals overning trafiic from said sidings into said stretch, a line relay for each signal, control circuits for each line relay extending to the opposite end of said stretch of track, a control relay at each end of said stretch of track, a stick relay at each end of said stretch of track acting when energized to break the control circuits for the line relay at the opposite end, a pick-up circuit for said stick relay including a front contact of the corresponding line relay and closed upon energization of the corresponding control relay, and another stick relay at each end of said stretch of track governed by the corresponding first-mentionedswitch to be cleared in preference to the opposing signal.

13. In a dispatching system, the combination with a track switch, signals adjacent said switch governing trafiic in opposite directions over said ;switch, means under the control of an operator at a distant point for clearing one or the other of said signals subject to trafiic conditions in advance thereof, and other means for causing the signal governing traffic toward the points of said j, switch to be cleared in preference to the opposing signal.

14. In a dispatching system of the type described, the combination with a single track section connecting two passing sidings, a starting :signal at each end of said single track section governing the entrance of traffic into that end of said section, means controlled from a central office which if operated tends to clear both of said signals, a stick relay for at times preventing clearing of the starting signal at the other end of said single track section, a pick-up circuit for said stick relay closed only if said means controlled from the central office is operated and there is a train present to the rear of said starting signals, and a stick circuit for said stick relay controlled wholly by said means controlled from the central ofiice.

15. In a dispatching system of the type described, the combination with a single track section connecting two passing sidings, a starting signal at each end of said single track section governing the entrance of traflic into that end of said section, means controlled from a central oifice which if operated tends to clear both of said signals, and means responsive to the presence of a train on themain track of one passing siding for clearing the starting signal at that end of said single track section in preference to the starting signal at the other end thereof.

16. In combination, a passing siding, a track switch at one end of said passing siding, a signal for governing movement of traffic away from said passing'siding, a stick relay forcontrolling said signal, manually controlled means for picking up said stick relay, and means efiective upon operation of said track switch for dropping said stick relay.

17. In a dispatching system of the type described, the combination with signals at the end of a passing siding governing traflic in opposite directions in accordance with the position of the track switch, two stick relays governing said signals, one stick relay having a back contact included in the energizing circuit of the other stick relay, and means operable from a distant 35 point for controlling said stick relay.

18. In a dispatching system of the type described, the combination with signals at the end of a passing siding governing traific in opposite directions in accordance with the position of the track switch, two stick relays governing said signals, one stick relay having a back contact included in the energizing circuit of the other stick relay, and means operable from a distant point for at times tending to energize one of said stick relays and at other times tending to energize both of said stick relays.

19. In a single track railway signalling system, the combination with a single track section containing signals for governing traffic in one direction and signals for governing traffic in the other direction, a stick relay at one end of said single track section for determining the clearing of a signal at the other end of said single track section, a second stick relay for controlling the first mentioned stick relay, means for controlling the second stick relay in accordance with the occupancy of the main track of the passing siding adjacent which said stick relays are located, and manually controlled means for controlling said stick relays.

20. In a single track railway signalling system, the combination with a single track section containing signals for governing traffic in one direction and signals for governing trafiic in the other direction, a stick relay at one end of said single track section for determining the clearing of a signal at the other end of said single track section, a second stick relay for controlling the first mentioned stick'relay, means for controlling the second stick relay in accordance with the occupancy of the main track of the passing siding adjacent'which said stick relays are located, and manually controlled means for at times tending to energize both of said stick relays, and at other times tending to energize only one of said stick relays. 7

21. In a single track railway signalling system, the combination with a single track section containing signals for governing trafiic in one direction and signals for governing traffic in the other direction, a stick relay at one end of said single track section for determining the clearing of a signal at the other end of said single track section, a second stick relay for controlling the first mentioned stick relay, means for controlling the second stick relay in accordance with the occupancy of the main track of the passing siding adjacent which said stick relays are located, and manually controlled means for at times tending to energize both of said stick relays, at other times tending to energize only one of said stick relays, and at still other times not tending to energize either of said stick relays.

WALTER W. WENHOLZ.

-D-ISOL.AI ME R 2,019,466.;Walter W. Wgnholz, Rochester, N. Y. TRAIN DISPATCHING SYSTEM FOR "RAILRQADSIJQ Patent dateil October 29, 1935. Disclaimer filed Oeuober 10, 1936, by the assignee, iGeneral Railway Signal Company. Hereby enters this disclaimer to clsi ims 6 and 17 of said Letters Patent,

[Ofiicial Gazette November 8, 1986.] 

